SUPERCRITICAL SOLUBILITY OF SOLIDS FROM NEAR-CRITICAL DILUTE-MIXTURE THEORY

A recently derived asymptotic theory for Henry's constant near the critical point of a solvent is adapted to the description of the solubility of solids in supercritical fluids. When solubility data for several systems are examined in the manner suggested by the theory, all the experimental isotherms for a given system (with the exception of a few near-critical points where the deviations are attributed to finite-concentration effects) collapse onto a single curve that is linear over a substantial range of solvent densities. This work provides a theoretical justification for some often-noted empirical relationships between solubilities and enhancement factors and the density of the supercritical solvent.